Finding the Fourth Proportional to 1,216.71, 1,825.52 and 485.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.71 : 1,825.52 = 485.89 : x
2. Step 2: Convert to fraction form
   1,216.71/1,825.52 = 485.89/x
3. Step 3: Cross multiply
   1,216.71x = 1,825.52 × 485.89
4. Step 4: Simplify right side
   1,216.71x = 887,001.91
5. Step 5: Solve for x
   x = 887,001.91/1,216.71
6. Step 6: Final answer
   x = 729.02